May Temperatures

Preliminary data indicates that the statewide average temperature in May was 61.8°F; this was 0.9°F below the 1981-2010 normal of 62.7°F (Figure 1). May was the second consecutive month to see below normal temperatures across the First State. Strong El Nino events, like we saw this winter, are often followed by cool spring temperatures across Delaware.

May Precipitation

Delaware’s statewide precipitation for May 2016 averaged 6.47 inches, 2.61 inches above the 1981-2010 mean (Figure 2). May 2016 was the 5th wettest May since records began in 1895, and the wettest month since June 2015.

Statewide Spatial Averages

Data from the Delaware Environmental Observing System (DEOS) shows that temperatures were below normal across the entire State, with the coolest temperatures (compared to normal) found across Sussex County, DE (Figure 3). Precipitation was significantly above normal across all of Delaware, with near normal precipitation amounts falling in Chester County, PA (Figure 4).

Figure 3. May 2016 average temperature departures (°F) from the 1981-2010 mean based upon DEOS station data.

Figure 4. May 2016 precipitation departures (inches) from the 1981-2010 mean based upon DEOS station data.